The present invention pertains to a cable saw with a frame, a motor drive and at least one drive wheel as well as a cable storage unit for a circulatingly driven sawing cable.
Such a cable saw has been known from WO 95/18692 or the parallel EP-BI 0 738 194. It comprises a frame, a motor drive and an integrated cable storage unit for an individual endless and circulatingly driven sawing cable. The sawing cable leaving the cable saw is led in a single loop around the workpiece and back again into the cable saw. The drive has a motor and an individual drive wheel, around which the sawing cable is wound. The sawing cable is tensioned by the cable storage unit functioning according to the principle of the pulley block with at least one stationary deflecting roller and a plurality of movable deflecting rollers corresponding to the progressing depth of cut on the workpiece, while the length of cable becoming free is taken up and stored. There may be problems in this arrangement with the reliability of operation and the stability of the cable saw and the sawing cable.
A wire saw, with which a rod-like tool is cut into a plurality of disks in one operation, has been known from JP-A 61 182 759. The finite wire is fed in for this from a wire reserve and clamped in the wire saw on a plurality of deflecting rollers in the form of a triangle. The wire is wound several times over the deflecting rollers, as a result of which a plurality of parallel wire strands, which make it possible to cut off a plurality of disk-shaped workpieces simultaneously, are obtained in the clamping and cutting area. The three deflecting rollers are driven together by a motor and are coupled with one another by means of a toothed belt gear.
The object of the present invention is therefore to provide a better cable saw.
According to the invention, a cable saw is provided with a frame, a motor drive and at least one drive wheel as well as a cable storage unit for a circulatingly driven sawing cable. The drive has a plurality of adjacent drive wheels over which the sawing cable is wound, The adjacent drive wheels are driven together by a motor.
The drive according to the present invention ensures high reliability of operation and stability of the cable saw and the sawing cable. The sawing cable is safely guided on a plurality of drive wheels, and the driving energy is transmitted to the sawing cable essentially without slip and wear. The drive makes do with a single motor, which optionally drives the drive wheels through an interposed transmission at equal speed. This arrangement is particularly economical and reduces the design effort and the space requirement. In addition, the control is simplified.
An especially economical and inexpensive design is obtained if the drive motor is arranged detachably at the cable saw via a suitable change-over coupling. The use of a plug-in quick coupling offers the advantage that rapid replacement and standardization of the interface between different machines are possible. As a result, the motor can be used alone or optionally in connection with the transmission, at different tool machines. The cable saw and other tool machines can thus be designed as inexpensive, driveless skeleton machines, which are then complemented with the motor and optionally the transmission when needed. It is advantageous in this connection for the drive motor to be designed as an electric motor.
The drive according to the present invention also offers special advantages in conjunction with the cable storage unit. This has a plurality of stationary and movable deflecting rollers. The use of double rollers with two grooves has the advantage that greatly different cable arrangements are possible. As a result, the capacity of the storage unit can be varied as desired. The space requirement and the design effort are minimized at the same time. The cable saw is not enlarged despite the great range of variation.
The roller arrangement according to the present invention as well as the special design of the cable inlet and outlet with oblique position and lateral offset offers improved guiding and kinematics for the sawing cable.
The cable saw can be advantageously broken down into at least three basic components, namely, a frame unit, a main roller head, and a motor unit, which may optionally also be designed as a more comprehensive drive unit including the drive wheels. The transport and the handling of the cable saw can be simplified and facilitated by these three or more basic components. Due to the lower weight, the individual components, in particular, can be transported and erected and mounted at the work site more easily. In addition, the space requirement of the cable saw taken apart is reduced.
Additional advantageous embodiments of the present invention are described in the subclaims.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which preferred embodiments of the invention are illustrated.